Provided herein compositions and methods for producing isoprenoids, including squalene. In certain aspects and embodiments provided are genetically converted yeast and uses therefore. In some aspects and embodiments, the genetically converted yeast produce isoprenoids, preferably squalene. Also are provided methods of producing squalene using a genetically converted yeast or a non-genetically converted yeast. The invention also provides squalene produced by genetically converted yeast or non-genetically converted yeast.